RU2303028C2 - Method for preparing lutein-containing composition, compositions and their using - Google Patents

Abstract

FIELD: special compositions.

SUBSTANCE: invention describes a method for preparing composition from microcrystalline lutein dispersed in cold water, its esters with fatty acids or their mixtures. Method involves dissolving lutein in food organic solvent in the presence of antioxidant, preferably tocopherol, and optionally vegetable oils at t° = 30-130°C. Compositions are stable against oxidation and soluble in hydrophilic and/or lipophilic media and can be used as dyes, food supplements and in cosmetics.

EFFECT: improved preparing method of composition.

17 cl, 4 ex

Description

The present invention relates to a new method for producing luteal compositions, mainly lutein esters and various fatty acids, starting from any natural or synthetic source, which give new valuable properties to these molecules, since they make it possible to obtain their stabilized compositions for direct use in food products, pharmaceuticals and cosmetics.

Traditionally, carotenoids are considered as pigments of plant origin. In fact, they are present in all green tissues in the form of photosynthetic pigment – protein complexes in chloroplasts. Despite the fact that the typical color of carotenoids from yellow to red is masked by the green color of chlorophylls, the typical color imparted by carotenoids can be observed in the leaves of many trees in the fall, when chlorophyll decomposes and xanthophylls esterify under the action of mixtures of fatty acids. With few exceptions, the carotenoids present in most leaves of all species are β, β-carotene, lutein, violaxanthin and neoxanthin. Of course, small amounts of other carotenoids, such as β, ε-carotene, β-cryptoxanthin, zeaxanthin, anteraxanthin, lutein 5,6-epoxide and lactucaxanthin, may also occur. Many flowers or fruits (tomatoes, oranges, peppers, marigolds, etc.), showing a color range from yellow to red, have their own color due to carotenoids in their chromoplasts and often present in a form esterified by fatty acids (G Britton, S. Liaaen-Jensen, H. Pfander, Carotenoids, Volume 1A: Isolation and Analysis, 201, Publ. Birkhauser, 1995).

Carotenoids can be divided into two classes: pure hydrocarbons called carotenes, which include compounds such as β-carotene, α-carotene, γ-carotene or lycopene and xanthophylls, molecules that contain oxygenated functional groups, examples of this type are astaxanthin, capsanthin, canthaxanthin or lutein. These two groups of compounds behave differently in terms of their physicochemical properties and solubility in organic solvents.

All these compounds play an important role in people's diets and their properties as antioxidants to prevent cancer and other human diseases and as provitamins A are widely studied. In addition, carotenoids, due to their yellow to red color, are used as food additives and dyes in margarine, animal oil, vegetable oils, soups, sauces, etc. (Ninet et al. Microbial Technology, 2nd Edn, Vol. 1, 529-544 (1979), Academic Press NY, Eds. Peppier H. J. and Perlman D.).

Lutein (3R, 3'R, 6'R) -β, ε-carotene-3,3'-diol is a carotenoid belonging to the group of xanthophylls or carotenoids with oxygenated functional groups. It is a polyunsaturated asymmetric molecule, which consists of a carbon skeleton similar to the skeleton of α-carotene ((6'R) -β, ε-carotene), but has β-hydroxyl on C-3 and α-hydroxyl on C-3 ' . Its empirical formula is C ₄₀ H ₅₆ O ₂ with a molecular weight of 568.85 and with the following molecular formula:

Lutein

In 1907, based on an analysis by burning, together with classical molecular weight determinations, the molecular formula C ₄₀ H ₅₆ O ₂ was proposed for a compound isolated from green leaves, which was called xanthophyll (R. Willstatter and W. Mieg, Liebig's Ann. Chem ., 335, 1 (1907)). Despite this, the formula C ₄₀ OH ₅₆ O ₂ for lutein isolated from egg yolk was proposed several years later (R. Willstatter and HH Escher, Z. Physiol. Chem. 76, 214 (1912)) and at that time it was not known that lutein and the compound previously isolated from the leaves and called "xanthophyll" are one and the same.

Until that moment, all attempts to elucidate the molecular structures of carotenoids through classical experiments on chemical degradation, until identifiable fragments were discovered, were unsuccessful. The highly unsaturated nature of carotenoids was confirmed several years later (1928) by means of catalytic hydrogenation experiments and then the term polyene (L. Zechmeister, L. Von Cholnoky and V. Vrabily, Ver. Deut. Chem. Ges ., 61, 566 (1928)). From this moment, a clear and direct relationship was established between the color and the number of conjugated double bonds present in these molecules (R. Kuhn and A. Winterstein, Helv. Chim. Acta, 11, 87; 116; 123; 144 (1928) and R. Kuhn and A. Winterstein, Helv. Chim. Acta, 12, 493; 899 (1929)).

The correct formula for lutein (or "xanthophyll") was established by Karrer in studies based on oxidative degradation reactions (P. Karrer, A. Zubrys and R. Morf, Helv. Chim. Acta, 16, 977 (1933)).

The instability of carotenoids in crystalline form is well known and one way to stabilize them is to obtain oil dispersions. Moreover, it is believed that when carotenoids are dispersed in oil, they are absorbed faster by the body.

An alternative way to stabilize unstable compounds is to microencapsulate them in starch matrices.

Thus, US patents 2876160, 2827452, 4276312 and 5976575 describe a significant increase in the stability of various compounds, including carotenoids, by encapsulating them in a matrix of starch.

One of the main difficulties in using carotenoids in the field of dyes is their zero solubility in water, since many of their applications take place in aqueous media. This solubility problem is mentioned in US Pat. No. 3,998,753 and is solved by preparing solutions of carotenoids in volatile organic solvents such as halogenated hydrocarbons and emulsifying them with an aqueous solution of sodium lauryl sulfate.

US Pat. No. 5,364,563 describes a process for preparing a carotenoid composition in powder form, which comprises forming a suspension of a carotenoid in a high boiling oil. The suspension overheats with steam for a maximum period of 30 seconds to form a solution of the carotenoid in oil. Next, using an aqueous colloid solution, this solution is emulsified, and then the emulsion is spray dried.

In general, the authors did not find in the modern literature lutein compositions that are resistant to oxidation during long periods of storage and, at the same time, are soluble in lipophilic or hydrophilic media, which make it possible to use them as dyes, for example, for food products pharmaceuticals and cosmetics or as food additives. Most commercial lutein samples consist of extracts or oleosmols from plants that have inadequate stability due to their limited antioxidant content. In addition, these oleosols are difficult to use in hydrophilic media because of their zero solubility in water, so their use is limited to applications in a lipophilic environment. In contrast, the compositions of the present invention exhibit high stability due to their controlled antioxidant content and are excellently applicable in both hydrophilic and lipophilic environments.

The present invention describes a method for the preparation, final processing or final presentation of lutein, related compounds (mainly lutein esters with various fatty acids) or mixtures thereof, obtained from any natural or synthetic source, depending on their final use, which consists in preliminary mixing with antioxidants in the presence of oils and / or organic solvents in appropriate proportions.

In accordance with this method, it is possible to obtain:

- microcrystalline suspension of lutein and / or related compounds in vegetable oil, suitable for use in lipophilic environments;

- CWD of lutein (lutein dispersible in cold water), suitable for use in hydrophilic environments.

Each of the variants of the method for producing the composition includes the following stages:

Microcrystalline suspension of lutein and / or related compounds in vegetable oil:

• Mixing vegetable oil with active molecules and an antioxidant.

• Grinding the mixture.

CWD lutein (cold water dispersible lutein):

• Molecular dissolution of lutein and / or related compounds in an organic solvent, preferably in the presence of antioxidants or vegetable oils, or both of them.

• Emulsification of an organic solution of active molecules with an aqueous solution of modified starches.

• Evaporation of the organic solvent and water to obtain a dry residue and an acceptable level of residual solvents.

• Drying and finishing of the product.

The method describes the preparation of these stable molecules, the stability of which is high enough (more than 6 months under appropriate packaging conditions), to prevent its oxidation during storage.

The main objective of the present invention is a method for producing various compositions that act in accordance with the characteristics of the application for which it is intended to use lutein and / or related compounds. This method involves pre-mixing microcrystalline lutein with antioxidants in the presence of oils and / or organic solvents in appropriate proportions.

The first composition, called a microcrystalline suspension of lutein in vegetable oil, consists of pre-mixed lutein molecules that must be contained in the composition, with various amounts of vegetable oil. A wide variety of vegetable oils can be used and the most common, but not the only ones, are sunflower oil, olive oil, corn oil, soybean oil, cottonseed oil, and the like. The dose of lutein and / or related compound will depend on the final strength that it is desired to achieve, the most common uses are suspensions with an active base content in the range between 5 and 60%, preferably between 10 and 30%. To increase the stability of the mixture, conventional lipid-soluble antioxidants, such as natural tocopherols and preferably D, L-alpha-tocopherol, are used. The proportion of this compound varies between 0.2 and 15% with respect to the weight of active molecules, preferably between 0.5 and 5%. In order for compositions containing lutein and / or related compounds to have satisfactory physiological activity, it is necessary to reduce the size of the crystals. This is achieved using conventional grinding systems applicable to liquid mixtures. A special objective of the present invention are ball mills that make it possible to reduce the size of crystals of less than 10 microns, preferably less than 5 microns and even more preferably less than 2 microns, using microspheres with diameters ranging between 0.5 and 0.75 mm. However, the size of the crystal may vary due to the specific use of the suspension, in each case the appropriate spheres and grinding conditions are used. The crystal size will also determine the rheological properties of the mixture, especially its viscosity, which can also be adjusted depending on requirements.

These microcrystalline suspensions of lutein and / or related compounds in oil are suitable for use in lipophilic environments.

A second composition, called a cold water dispersible lutein (CWD) composition, is based on the dissolution of lutein and / or related compounds in an organic solvent and its subsequent microencapsulation in modified starches. The present invention will relate, in particular, to the use of foodborne solvents that are considered natural, such as acyl esters, preferably ethyl, propyl, isopropyl, butyl or isobutyl acetates, which combine reasonably high solubility for carotenoid components with compatibility as solvents included in the class III ICH group. These solvents are approved both nationally and internationally in the fields of both pharmaceuticals and food products (RDL12 / 04/90 and RDL16 / 10/96). According to ICH, the content of residual solvents should be lower than 5000 ppm, preferably lower than 1000 ppm, and more preferably lower than 100 ppm, always with respect to the dry material in the liquid mixture. The concentration of lutein and / or related compounds in the organic solvent may vary between 1 and 50 g / l, preferably between 10 and 30 g / l. The dissolution temperature may vary between room temperature and the boiling point of the solvent, preferably between 20 and 130 ° C. The fact that the percentage of cis-lutein is a function of the temperature / time ratio during the operation of dissolving the molecules in an organic solvent means that if we want to obtain a product with a low content of this isomer, either a low dissolution temperature should be used, or in another case, a very short time dissolution. Thus, in order to achieve low levels of the cis isomer and due to the relatively low solubility of these compounds in solvents of this type (acyl esters) at temperatures of the order of 20-40 ° C, dissolution should preferably be carried out between 70 and 130 ° C over a few seconds. It should be noted that the trans isomer is a natural isomer and that there are differences in color shades between the two isomers. On the other hand, if the levels of the cis isomer are not important, dissolution without restrictions on its conditions can be carried out rather than achieving complete solubility at the molecular level. Alternatively, it is possible to use a solvent with greater solubility for these molecules at relatively low temperatures (20-35 ° C), such as chloroform, methylene chloride, THF and the like. In this case, dissolution can be carried out at a low temperature (about 30 ° C) for several minutes without any risk of the formation of cis isomers in excessively high proportions. To increase the stability of the final composition, an antioxidant or a mixture of several antioxidants, preferably such as tocopherol, ascorbyl palmitate and the like, each of them in a ratio of between 1 and 30%, preferably between 10 and 20%, relative to the weight of the active molecules, soluble with lutein and / or related compounds in an organic solvent. It is also possible to incorporate vegetable oil, that is, sunflower oil, olive oil, corn oil, soybean oil, cottonseed oil and the like, into the mixture in order to facilitate the dissolution of lutein and / or related compounds and give the composition additional stability. The lutein / oil ratio may vary between 10/1 and 1/10.

A solution of the active molecules thus obtained is mixed and emulsified together with an aqueous solution containing an emulsifying agent, for example, modified starch, more specifically, esters derived from starch, preferably octenyl succinates obtained from starch with different molecular weights, in particular, but not exclusively, Purity Gum 2000® from National Starch or Cleargum CO 01® from Roquette, and a microencapsulating agent obtained, for example, from modified starch, more specifically, esters derived from starch, preferably meaningfully octenyl succinates derived from starch of various molecular weights, in particular, but not exclusively, Hi Cap 100® or Capsul®, from National Starch. The mixing ratio of the emulsifying agent and the microencapsulating agent may vary between 5/95 and 95/5, preferably between 25/75 and 75/25, and more preferably between 40/60 and 60/40. The water content for each of the components of the mixture of emulsifying agent and microencapsulating agent varies and can be between 1 and 30%, preferably between 5 and 20%, and more preferably 10%. The mixture of aqueous and organic phases is emulsified and the resulting emulsion is homogenized using pressure homogenization systems such as Manton Gaulin or Microfluidizer, which are commonly used, and preferably by homogenization using tangential friction, for example using an Ultraturrax emulsifier, over a period of time that varies in accordance with the energy supplied by the equipment and the volume of the mixture to be emulsified in order to obtain an average micelle size of less than 10 microns, preferably more than 2 microns, and more preferably between 0.1 and 1 microns.

After forming the emulsion, the organic solvent is evaporated, preferably by vacuum distillation at a temperature below 50 ° C. When solvent evaporation takes place, microcrystallization of the active molecules in the starch matrix occurs. After evaporation of the solvent, evaporation is continued with successive additions of water until a residual solvent content is obtained that satisfies the conditions for the maximum concentration specified in the policy documents and a dry residue which is suitable for the type of drying to be applied to this liquid mixture. The corresponding dry material values of the microencapsulated lutein suspension and / or related compounds are between 1 and 30%, preferably between 10 and 25%.

It was found in accordance with the present invention that both the high-temperature spray drying method (dispersion) and the fluidized-bed spray method (granulation) are suitable for drying an aqueous suspension of the obtained active molecules. Another alternative would be freeze-drying.

According to the dispersion drying method, the respective inlet air temperatures for drying should be between 100 and 200 ° C, while the outlet temperatures should be between 60 and 120 ° C. The finely ground product has a particle size between 10 and 100 microns. To increase the particle size and, thus, to reduce the available surface area and, therefore, to increase the oxidative stability of the product, the finely ground product can undergo a final processing process including agglomeration by spraying a solution of one of the modified starches used in the composition, or suspensions of microencapsulated active molecules in the fluidized bed of the specified finely divided product, which makes it possible to achieve particle sizes in between 50-500 microns, and preferably within 200-300 microns.

The granulation method involves the use of a fluidized bed granulator, in which seed material is placed, which may be a regular inert material, such as sugar particles, or a fine powder of the material itself, which must be dried, obtained in earlier granulation operations or at the spray drying stage. Particles are maintained in motion by air, and the temperature of the layer is maintained between 30 and 90 ° C, preferably between 50 and 80 ° C. A suspension of lutein and / or related molecules is sprayed by means of air, preheated to a temperature between 20 and 140 ° C, in a fluidized bed at such a speed that ensures that the particles to be coated are not wetted excessively and do not form lumps. The granular product has a particle size in the range between 100 and 2000 microns, preferably between 100 and 800 microns, and more preferably between 100 and 300 microns.

Upon completion of the spray drying step using one method or another, as well as optional agglomeration, the resulting particles can undergo a final process by coating. This coating can be carried out using approximately 0.5-10%, by dry weight, aqueous solutions of sugars or even starches.

Example 1

Netzsch type Minizeta 003 laboratory ball mill is charged in the indicated order with microspheres with a diameter of 0.5-0.75 mm, 30 g of sunflower oil (Koipe), 0.08 g of D, L-alpha-tocopherol (Merck) and 20 g of complex Xantopina Plus luteal ester (Bioquimex), which has an equivalent lutein content of 40%. The mixture was stirred at 3000 rpm for 5 minutes to give 45 g of an orange viscous liquid. Spectrophotometric analysis of the oil suspension shows a lutein content of 15%. The crystal size is less than 10 microns.

Example 2

20 g of Xantopina Plus lutein ester (Bioquimex), which has an equivalent lutein content of 40%, are resuspended in 410 ml of isobutyl acetate and 0.8 g of D, L-alpha-tocopherol (Merck) is added. The mixture is heated to boiling (114 ° C) for 2 minutes, achieving complete dissolution of the solid product. As a parallel operation, 26.65 g of Hi Cap 100® (National Starch) and 26.65 g of Purity Gum 2000® (National Starch) are dissolved in 325 ml of demineralized water. The hot organic phase is emulsified for 10 minutes in one step in the aqueous phase using an Ultraturrax emulsifier from IKA, obtaining an average micelle size of 0.4 microns, measured using a Coulter LS230 analyzer. The emulsion is transferred to a vacuum distillation system by adding 600 ml of water, so that 410 ml of isobutyl acetate is evaporated with approximately 700 ml of water. 225 g of a liquid preparation (25.9% of dry material) are obtained with an equivalent lutein content of 2.6% (10.1% with respect to dry weight). This liquid preparation is dried in an Aeromatic AG laboratory granulator using an inlet gas temperature of 90 ° C and reaching a product temperature of 70 ° C, an orange powder is obtained with an equivalent lutein content of 9.7% and a water content of 2.6%.

Example 3

20 g of Xantopina Plus lutein ester (Bioquimex), which has an equivalent lutein content of 40%, are resuspended in 410 ml of isobutyl acetate and 0.8 g of D, L-alpha-tocopherol (Merck), 1.6 g of ascorbyl palmitate (Merck) are added. and 8 g of sunflower oil (Koipe). The mixture is heated to boiling (114 ° C) for 2 minutes, achieving complete dissolution of the solid product. As a parallel operation, 21.5 g of Hi Cap 100® (National Starch) and 21.5 g of Purity Gum 2000® (National Starch) are dissolved in 325 ml of demineralized water. The hot organic phase is emulsified for 10 minutes in one step in the aqueous phase using an Ultraturrax emulsifier from IKA, obtaining an average micelle size of 0.5 microns, measured using a Coulter LS230 analyzer. The emulsion is transferred to a vacuum distillation system by adding 600 ml of water, so that 410 ml of isobutyl acetate are evaporated with approximately 700 ml of water, and 205 g of a liquid preparation (25.0% dry material) with an equivalent lutein content of 2.5% (10.0%) are obtained in relation to dry weight). This liquid preparation was dried in an Aeromatic AG laboratory pellet mill using an inlet gas temperature of 90 ° C and reaching a product temperature of 70 ° C to obtain an orange powder with an equivalent lutein content of 9.5% and a water content of 3.0%.

Example 4

20 g of Xantopina Plus lutein ester (Bioquimex), which has an equivalent lutein content of 40%, are resuspended in 500 ml of dichloromethane and 0.8 g of D, L-alpha-tocopherol (Merck) is added. The mixture is heated at 35 ° C for 5 minutes, achieving complete dissolution of the solid product. As a parallel operation, 26.65 g of Hi Cap 100® (National Starch) and 26.65 g of Purity Gum 2000® (National Starch) are dissolved in 400 ml of demineralized water. The hot organic phase is emulsified for 10 minutes in one step in the aqueous phase using an Ultraturrax emulsifier from IKA, obtaining an average micelle size of 0.5 microns, measured using a Coulter LS230 analyzer. The emulsion is transferred to a vacuum distillation system by adding 600 ml of water, so that 500 ml of dichloromethane is evaporated together with approximately 800 ml of water. Get 200 g of a liquid preparation (26% dry material) with an equivalent lutein content of 2.6% (10.0%, relative to the weight of dry material). This liquid preparation was dried in an Aeromatic AG laboratory pellet mill using an inlet gas temperature of 90 ° C and reaching a product temperature of 70 ° C to obtain an orange powder with an equivalent lutein content of 9.8% and a water content of 2.0%.

Claims (17)

1. A method of producing a CWD cold water dispersible lutein (CWD) composition, its esters with fatty acids or mixtures thereof, obtained from any source, either natural or synthetic, including: a) dissolving lutein in an edible organic solvent in the presence of antioxidants and, optionally, vegetable oils, at temperatures ranging from 30-130 ° C, depending on the solvent used, b) emulsifying and microencapsulating the organic solution obtained in the previous step using an aqueous solution of modified starch by using homogenizing agents, c) evaporating the organic solvent and water until a residual amount of solvents in accordance with commercial food standards is reached, and d) drying and finishing. 2. The method according to claim 1, characterized in that, preferably, tocopherol or ascorbyl palmitate is used as an antioxidant in a proportion of 0.2 to 30%, preferably in the range of 10-20%. 3. The method according to claim 1 or 2, characterized in that the lipid-soluble antioxidant compounds are used, in a ratio of between 0.5 and 10%, based on the mass of lutein in the mixture. 4. The method according to any one of claims 1 to 3, in which the oil used is of vegetable origin, preferably is a sunflower oil, olive oil, corn oil, cottonseed oil, peanut oil or soybean oil. 5. The method according to claim 1, characterized in that the organic solvent used is preferably selected from the following solvents: methylene chloride, chloroform, THF, ethyl acetate, propyl acetate, isopropyl acetate, n-butyl acetate or isobutyl acetate. 6. The method according to claim 1, in which the material obtained in the evaporation step c) has a residual organic solvent content lower than 5000 ppm, preferably lower than 1000 ppm, and more preferably lower than 100 ppm, based on the dry material of the suspension. 7. The method according to claim 1, characterized in that starch esters, preferably octenyl succinate and starch derivatives are used as emulsifying / microencapsulating agents. 8. The method according to claim 1, characterized in that the drying of the liquid suspension is carried out by dispersing at temperatures in the range of 100-200 ° C for inlet air and 60-120 ° C for outlet air. 9. The method according to claim 1, characterized in that the drying of the liquid suspension is carried out by spraying in a fluidized bed at temperatures for the layer in the range of 30-90 ° C, and preferably 50-80 ° C, the suspension is sprayed over the specified layer using air, preheated to 20-140 ° C. 10. The method according to claim 1, characterized in that the drying of the liquid suspension is carried out by freeze-drying. 11. The method according to claim 1, characterized in that the final processing includes coating the particles using aqueous solutions of various sugars or modified starches. 12. A composition intended for use as a dye or food additive, obtained in accordance with the method according to any one of claims 1 to 11, characterized in that it consists of granules of lutein microcrystals and / or its esters with fatty acids having an average microcrystal size, measured as an average micelle size of less than 10 microns, preferably smaller than 2 microns, and more preferably in the range between 0.1 and 1 microns, and with an average granule size in the range of 100-2000 microns, preferably within 100-800 m m, and more preferably in the range 100-300 microns. 13. A composition intended for use as a dye or food additive, obtained in accordance with the method according to any one of claims 1 to 11, characterized in that it contains a finely divided product of microcrystals of lutein and / or its esters with fatty acids, having an average microcrystal size, measured as an average micelle size, less than 10 microns, preferably less than 2 microns, and more preferably, between 0.1 and 1 microns, with an average particle size of the finely divided product in affairs 10-100 microns. 14. A composition intended for use as a dye or food additive, obtained in accordance with the method according to any one of claims 1 to 11, characterized in that it contains an agglomerate of a finely divided product from lutein microcrystals and / or its esters with fatty acids, having an average microcrystal size, measured as an average micelle size, less than 10 microns, preferably less than 2 microns, and more preferably, between 0.1 and 1 microns, with an average agglomerate size of 50-500 microns, pre respectfully, in the range 200-300 microns. 15. The composition according to any one of paragraphs.12-14, characterized in that it is coated with aqueous solutions of 0.5-10% of dry weight, sugars or modified starch. 16. The use of any of the compositions according to claims 12-15 as colorants, in particular in food products, pharmaceuticals and cosmetics. 17. The use of any of the compositions according to claims 12-15 as food additives.